1. Field
The present disclosure relates to an electronic device including an organic semiconductor element and a method of making the same.
2. Description of the Related Technology
Active matrix organic light emitting displays (OLEDs) typically include thin film transistors (TFTs) for pixels. In order to reduce manufacturing costs, organic thin film transistors (OTFTs) can be used. A plurality of OTFTs are arranged in a matrix form. OTFTs have channels formed of an organic semiconductor (OSC) material.
In forming the channels of OTFTs, an organic semiconductor layer is formed on a substrate. The organic semiconductor layer can be patterned to separate the channels of neighboring OTFTs. As disclosed in GERWIN H. GELINCK et Al. “FLEXIBLE ACTIVE-MATRIX DISPLAYS AND SHIFT REGISTERS BASED ON SOLUTION-PROCESSED ORGANIC TRANSISTORS,” Nature Materials 3, 106.110 (2004), patterning of an OSC material is desired to achieve good single transistor performance such as a high on/off current ratio. The patterning can also prevent unwanted cross talk effect between adjacent TFTs and between conductive lines in an electronic circuit of an OLED. A non-patterned semiconductor material can cause current leakage.
Direct patterning technologies such as additive printing can be used to pattern an OSC material. Examples of the additive printing include inkjet (I/J) printing and flexo printing. However, the printing methods often cause a non-uniform OSC layer profile due to, for example, drying of an ink. Therefore, a large OTFT-to-OTFT thickness variation can occur which reduces the uniformity of the brightness of the display. An alternative way is to use photolithography including etching processes. However, these processes are complicated, expensive and can damage an OSC material.